A luminaire is generally understood to include one or more light producing subsystems carried by a housing along with power, driving, and/or power distribution devices. In this manner, the luminaire provides a single unit that is easy to install and/or ship. An example of a luminaire is a light fixture, such as a hanging light fixture commonly installed to hang from a ceiling or wall. However, there are many different types of luminaires, and the luminaires discussed herein are to be considered representative of all such devices.
In the past, luminaires used to provide relatively high levels of light for relatively large areas, such as outdoors, along driving surfaces such as parking lots, roadways, and tunnels, as well as in industrial areas and warehouses, have often had high-intensity discharge (HID) lamps as the primary light source. HID lamps, in general, are based on passing an electric arc between two spaced apart electrodes within a transparent or translucent arc-tube filled with a gas and/or salts that form intense plasma light when excited by the electric arc. Various examples of such HID lamps include mercury-vapor lamps, metal-halide lamps, ceramic metal-halide lamps, sodium vapor lamps, and xenon lamps.
Today, the use of light emitting diode (LED) based lighting systems for luminaires is becoming increasingly commonplace due to their energy efficiency and life span in comparison to other types of light sources, including many common HID lamps. Because of the potential long term energy and cost savings, it is often desired to replace existing installed HID lamps with LED lights.
When the HID lamp is disposed within and/or carried by a housing of a luminaire, this change out could be accomplished by replacing the entire HID luminaire with a new LED luminaire. For customers that have very large numbers of luminaires, however, the up-front cost of such a changeover can be extremely high.
In order to save costs and re-use existing hardware, it may be possible to retrofit an HID-based luminaire with an LED lamp. Such a retrofit can include removing the HID lamp and associated driving equipment from the luminaire housing and replacing it with an LED lamp assembly and associated driving equipment, thereby re-using the existing luminaire housing and support structures. However, such a change out of the lighting system is often very labor intensive. In addition, the difference in heat production and dissipation mechanisms between an HID-based luminaire and an LED-based luminaire can raise additional difficulties when attempting to retrofit an HID luminaire with an LED lamp assembly. This difficulty arises primarily from the fact that HID lamps generally rely on radiation from the reflector to expel the heat out of the luminaire, whereas LED lamp assemblies often rely on conduction to expel heat from the luminaire. Thus, the difference in heat dissipation mechanisms can also make it more complex to retrofit an LED lamp assembly into the housing of an HID-based luminaire.